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From: jwag@moose.asd.sgi.com (Chris Wagner)
Newsgroups: comp.sys.sgi
Subject: Re: vhand
Keywords: vhand
Message-ID: <1990Sep21.161455.28464@odin.corp.sgi.com>
Date: 21 Sep 90 16:14:55 GMT
References: <amys.653844988@TheImprov>
Sender: news@odin.corp.sgi.com (Net News)
Reply-To: jwag@moose.asd.sgi.com (Chris Wagner)
Distribution: comp
Organization: Silicon Graphics, Research & Development
Lines: 31

In article <amys.653844988@TheImprov>, amys@ncsa.uiuc.edu (Amy Swanson) writes:
> 
> 
> Does anyone know what the "vhand" process does?  It always runs from PID 2,
> but I can't find any information on it in the manuals.  The reason I'm
> asking is that we've recently had the vhand process get out of hand and "take
> over the system."  It was chewing up lots of CPU time and made it impossible
> to log into the system other the network.  We sent the process a "kill -1" 
> which seemed to fix it, but I'd like to know why this happened.
> 
> 
> Thanks in advance,
> Amy
> 
> 
> Amy Swanson
> SGI Systems Administrator
> NCSA - National Center for Supercomputing Applications
> University of Illinois @ Urbana-Champaign
> amys@ncsa.uiuc.edu

vhand is the paging process - it is a system, process, and as such 
does not catch signals, etc..  The only way (unless theres a bug!) that
it can take onver the system is if a user process is using
so much memory and has such poor locality that the system thrashes.
In this case it would be vhand that thrashes - always paging out the page that
the user wants next!

You may wish to try to understand what was running at the time (using ps say)

Chris Wagner